Wire feeder for nail machines



INVENTOR Charla-5R. Chism 2 Sheets-Sh eet 1 u llIl 13.

c. R. CHISM WIRE FEEDER FOR NAIL MACHINES F 1 d May 5 1942 March 30,1943.

March 30, 1943. C c s 2,315,108

WIRE FEEDER FOR NAIL MACHINES Filed May 1942 2 Sheets-Sheet 2 4a .1 2g.2. 30 1H 46 10 x L -4 if. I l 122 INVENTOR Charleslf, Chism W fimey.

, being positioned Patented Mar. 30, 1943 UNIT ED STATES PATENT OFFICE2,315,102; i

wmE FEEDER FOB NAIL, MAcnmEs Charles a. 'Chism, Pittsburg, Calif.Application May 5, 1942, Serial No. 4413865 3 Claims. (01.

v This invention relates to improved means for feeding wire or rod stockto a nailmaking machine. More specificallythe present inventioncontemplates specific features of design and arrangement particularlydescribed in the following specification, shown in the accompanyingdrawings and defined with particularity in the appended claims.

In the drawings:

7 Figure 1 is a perspective improved feeder;

Figure 2 is a plan view illustrating the feeder;

Figure 3 is a cross section on line III-1 11 of Figure 2;

Figure 4 is an enlarged detail of the gripping device of the presentinvention; and

Figure'5 is a view similar to Figure 4 illus devices used in the priorart nail making machines.

Referring in detail to the drawings, the apparatus includes a rollerholder lIl having a slot I2 which extends inwardly The holder ispivotally mounted on a steel post I8 carried by a reciprocating feedtable I8. This post passes freely through the hole It to provide fornecessary clearance, marked C in Figure 3, to insure proper operation ofthe coacting parts. A particular novel feature of the invention residesin the provision of an anti-friction ball bearing roller 20 carried by aspindle 22 and having bearing balls 24 which make a rollingantifrictioncontact with the Spindle 22, the roller in the slot I2 and the spindlebeing rigidly secured to the holder III. The respective sizes of theroller and the holder are such that the periphery of the roller extendsslightly beyond the outer portion of the holder. The ball bearing roller20 bears firmly on the post I8 on the forward wire feeding stroke of thetable, and during the back stroke the clearance C permits the holder toshift with respect to the post a to the post hole I4.

this action there is provided theholder I; Thus sufficient distance torelease the pressure and thus free the rollergrip on the post. To,insure a spring 28 which surrounds the post I8 and has one end anchoredthereto at 30. The other end 32 of the spring is engaged with a stud 34extendedoutwardly from the spring normally tends to turn the holder I0counterclockwise, as viewed view of a portion of a nail rnaking'machineequipped with the improved an oscillating arm 38 forward stroke of thewith the feed table in Figure 2.

The post I8: and holder move back and forth l8 which in turn slides insuitable fixed ways 31, the'table being actuated by having a forked end40 which straddles a bolt 42 secured to the table and passing through agroove 44 of a wire guide member 46.

In normal operation, throughout both the forward and return strokes, theroller 20 'contacts the wire stock W to be fed, this contact beingmaintained by the spring-28 surrounding the post l8. The resultingpressureof the spring, coupled with the friction developed between theroller and the wire during travel, causes theroller and the holder II!to move toward the steel post as the table travels toward the nail diesconventionally indicated at 48. Since the radius of the roller isgreater than the distance between the roller center and the post holecircumference, the roller contacts with the steel post. The resultingpressure at this point bind the roller to the steel post and preventrotation of the roller. .Since the roller cannot rotate, it will tend togrip the wire. Thus upon the table IS the wire will be ad.- vaned towardthe dies 48. Figures 3v and 4 show the parts in the feed position.During the return stroke the parts take the position of Figure 5, thefriction-between the wire and the roller acting in the oppositedirection. This will tend to twist the roller away from the steel post.Thus, because of the allowed clearance at the steel post hole, theroller is moved free of the post and is allowed to turn on its axis andthus 'roll along the wire as the feed table returns to its initialposition.

It will be apparent that after eachfeeding stroke a slight turningmovement is imparted to the roller. This results in periodicallypresenting a different wear surface of the roller to the wire ateachstroke of the machine. This is ad- ,vantageous because itaddsgreatly to the.life of the wire engaging part of the nail machine.

of contact is great enough to the wire stock in said guide differentposition each. time the wire'is engaged and the rolling contact preventsthe marring or scratching oflthestock and thus overcomes an in herentdefect in the conventional feeding device heretofore used.

Having thus described my invention, what 'I" claim is: v p

1. A feeder for wire stock comprising a feed table having agroovedl'guide for the wire stock, means for imparting forward andbackward ing a post carried by the table, said holder having a bearingopening therein of larger diameter than the post to provide a clearance,a roller journaled in the holder and coacting vwith the post ,to gripupon forward'movestock forward; a spring tending to turn said 7 strokesto said table, a holder pivotally engagment of said table, aspring'tending to turn the holder about said post in a directiontowardthe 7 wire stock and also effective upon the back stroke of thefeedtableto shift the holder with} relation to said post to an extent permittedby saidclearanceto thus free the grip of thefroller upon the post andthereby cause the, roller to'tlurn as it rides on the wire during theback stroke of the table.

v 2. A feeder for wire stock comprising a feed table having a groovedwire guide a pivot post 5 secured to the table, a holder having abearing opening of larger diameter than the post to pro-- vide aclearance, a Wire engaging roller journaled, on a spindle carried bysaid holder and having bearing balls incorporated therein for antifrlction contact with said spindle, the periphery of,

said roller contactingboth the post and the wire stock in said guideupon theiorward movement of said table to thereby grip and move saidwire roller about said post in a direction toward said wire stock andalso effective upon the back stroke of the feed table to shift theholder with relation to said post to an extent permitted by saidclearance to thus free the grip of the roller upon the post and therebycause the roller to turn as it rides on the wire stock during said backstroke of the table.

3.In a nail making machine, a feeder for the awire nail stock comprisinga feed table carrying a grooved guide, means for imparting forward andbackward strokes to said table, a post secured to the table, a holderhaving a bearing opening therein for coaction with the post and oflarger diameter than the post to provide a clearance, a ball bearingwire engaging roller carried by a spindle secured to said holder andcoacting with said post 'to grip the wire stock in said guide upon theforward movement of said table, a torsion spring having one end engagedwith the post and the other end connected to the'holde'r and tending toturn it about the post'inra direction toward said wire stock and alsoeffective upon the back, .strokeof the feed table to shift the holderwith relation to the post to an'extent permitted by said clearance tothus release the grip of the roller upon the post and thereby cause theroller to turn as it travels along the wire stock during the backstroke'of the table whereby upon subsequent strokes of thevfeed tabledifferent portions of the-periphery of the roller will successively comeinto gripping engagementwith the wire stock and thus distribute the wearand consequently lengthen the useful life of the roller.

HARLES R. CHISM.

